BEGINNER'S GUIDE TO CHOOSING ROUTER BITS

I've got a router, but which bits should I buy?

You’ve finally got that new router, and you’re eager to use it. High-tech as it is, though, it’s toothless without router bits. But which bits should you buy? If you haven’t used a router much, the options can be dizzying. Here’s what you need to know to make informed choices.

First, router bits come in many profiles. That’s the term for the shape of the cutting edge. Here are some of the most common:

Straight Bits: A workshop staple, these bits make cuts straight into a material to form a groove or dado (a groove across the wood grain) or to hollow out an area for a mortise or inlay. They come in a variety of diameters and lengths.

Rabbeting Bits: Guided by a spinning pilot bearing at the tip, these bits are designed specifically to cut a rabbet (shoulder) in the edge of a workpiece often used to join pieces. They can be purchased in a set that includes bearings of different diameters, allowing a single bit to produce rabbets of different sizes.

Flush-Trim Bits: As the name suggests, these bits are used to trim the edge of one material flush with the edge of another– for example, trimming a veneered surface flush with a substrate or using a pattern to create multiple identical pieces. They usually are guided by a pilot bearing that’s the same diameter as the cutter. The bearing may be at the tip of the bit or at the base.

Chamfer Bits:These bits cut a bevel of a particular angle to ease or decorate the edges of a surface. They also can create the beveled edges needed to join multi-sided constructions.

Edge-Forming Bits:As the name suggests, edge-forming bits are most often used to cut a decorative edge. For example, Round-Over bits cut a rounded edge of a particular radius (such as 1/8" or 1/4"); Ogee bits cut variations of an S-shaped profile; Edge-beading bits cut a quarter- or half-circle profile (called a bead); Cove bits cut a concave quarter-circle. Many edge-forming bits include a pilot bearing. In most cases, these bits are used for final decoration of a project where edges have already been established and can serve as guides for the bit.

Specialized Bits:This category includes bits dedicated to specific tasks. Examples are molding bits, which incorporate multiple edge-forming profiles into a single bit; stile-and-rail bits, which are used to shape the frame pieces in frame-and-panel constructions such as cabinet doors; and raised-panel bits, which shape the edges of a door panel to fit into the corresponding slot in the frame’s stiles and rails. These bits are somewhat large and can be used safely only in a table-mounted router. Other specialized bits include dovetail bits, drawer-lock bits, finger-joint bits and lock-miter bits.